For a wide range of applications of lithium ion batteries, a mechanism for isolating large current loads is useful to protect both the batteries and the powered device resulting from the occurrence of a critical event. Exemplary critical events may include a reversal of polarity when the terminals of the battery are connected backwards, a short circuit resulting from positive and negative terminals being linked together by a conductor, an overcharge condition that results from continued battery charging after a battery cell is fully charged, a forced discharge condition that results from one of the battery cells reaching a minimum specified cell voltage, or an over temperature condition when any cell in the battery exceeds a predetermined temperature. These critical events can lead to safety issues and other issues that can harm the battery and/or the device being powered.
It would be beneficial to provide a device to isolate a battery from its powered device when a critical event occurs.